Enables several functions, including RNA polymerase II-specific DNA-binding transcription factor binding activity; chromatin binding activity; and transcription corepressor activity. Involved in several processes, including cerebral cortex neuron differentiation; negative regulation of circadian rhythm; and regulation of axon extension. Acts upstream of or within several processes, including cellular response to glucose stimulus; positive regulation of G2/M transition of mitotic cell cycle; and response to methylglyoxal. Located in kinetochore and nucleus. Part of transcription repressor complex. Is expressed in several structures, including central nervous system; early conceptus; genitourinary system; and retina. Human ortholog(s) of this gene implicated in chromosome 15q24 deletion syndrome. Orthologous to human SIN3A (SIN3 transcription regulator family member A). [provided by Alliance of Genome Resources, Apr 2022]